Method of and machine for shaping metal to form a flange

ABSTRACT

A method of and a machine for forging sheet metal at bends therein, which method employs a machine which includes an element having a groove for receiving the heated metal to be forged and includes an element which extends into the groove, which latter element includes sections which engage several spaced portions of the metal to apply pressures on the metal to cause it to flow toward the bend. More specifically the method also comprehends first shaping the flat sheet metal to approximately its ultimate shape by cold working and thereafter heating the metal to its forgeable temperature before subjecting it to the aforementioned forging machine.

United States Patent [72] Inventor Neville T. l-lenkel 9582 Labradore Lane, El Cajon, Calif. 92021 [21] Appl. No. 835,493 [22] Filed June 23, 1969 [45] Patented Dec. 28, 1971 [54] METHOD OF AND MACHINE FOR SHAPING METAL TO FORM A FLANGE 12 Claims, 11 Drawing Figs.

[52] U.S. Cl 72/177, 72/ 1 99, 72/200, 72/366 [51] Int. Cl ..B2lb 15/00, B21d 1/02 [50] Field of Search 72/ 199, 202, 200,366,177, 179, 182, 225

[56] References Cited UNITED STATES PATENTS Rel6,097 6/1925 Grey 72/366 X 623,479 4/1899 Kennedy 72/202 l i a g 5 Primary Examiner-Milton S. Mehr Attorney-Warren H. F. Schmieding ABSTRACT: A method of and a machine for forging sheet metal at bends therein, which method employs a machine which includes an element having a groove for receiving the heated metal to be forged and includes an element which extends into the groove, which latter element includes sections which engage several spaced portions of the metal to apply pressures on the metal to cause it to flow toward the bend. More specifically the method also comprehends first shaping the flat sheet metal to approximately its ultimate shape by cold working and thereafter heating the metal to its forgeable temperature before subjecting it to the aforementioned forging machine.

PATENTED UEC28 1971 SHEET 1 0F 3 INVENTOR.

NEVILLE T. HE/VKEL ATTORNEY BY Mm- PATENTEU 05628191! 3.630.059

SHEET 3 OF 3 INVENTOR. w

A TTORNE Y METHOD OF AND MACHINE FOR SHAPING METAL TO FORM A FLANGE BACKGROUND OF THE INVENTION 1 Field of the Invention The invention is directed to the art of selective shaping of sheet metal, selective in that the major portion of the shaping to that desired is by the standard cold forming operation or operations, for example by a press brake or rollers or a combination of both. Such preforming operation often results in stretching the metal at the bend or bends to such extent that grain growth and fissures are formed. The selective shaping also includes forging the metal primarily at angularly disposed portions or bends of the preformed metal to create an interlocked, forged grain structure at those portions or bends.

2. Description of the Prior Art Heretofore it has been the practice of either forging the entire metal to the ultimate shape or by employing bar stock and machinery that stock to the desired ultimate shape. Both of the foregoing processes were highly uneconomical. In the complete forging operation constant heat had to be applied. One example of rolling and forging is disclosed in the French Pat. No. 1,343,889, wherein the entire metal must be forged.

In the machining process, all metal that was removed was in the form of scrap metal. Some of the present alloys of metal required in certain structures are high in cost and, therefore, the cost per pound of the finished product is excessive due to the necessity of scrapping. In many cases more scrap metal, by weight, results from the bar than the weight of the product produced.

SUMMARY OF THE INVENTION The machine of the present invention, which is used for carrying out the new method, comprises an element having a groove, such as a grooved roller, and a second element, such as a roller, which extends into and spans the width of the groove. The second mentioned element includes a section, at least one side thereof being spaced from one of the sidewalls and the bottom wall which form the groove. The second mentioned element includes a second section which is disposed along the said one sidewall of the first mentioned portion of the second mentioned element and is spaced a greater distance from the bottom of the groove than the first mentioned section. The metal is preheated, at least at the bend, to a temperature at which the heated metal is in a forgeable state. These sections engage different portions of the metal with sufficient pressure to effect flow of the metal into the bend portion thereof, resulting in interlocking, forged grain structure in the bend.

Other features and the advantages of the present invention will be apparent from the following description, reference being made to the accompanying drawings wherein preferred embodiments of the invention are illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of the two forging elements in the form of rollers, showing the same in cooperative relationship and showing the sheet metal being forged;

FIG. 2 is a view looking in the direction of arrows 2 in FIG. I, and a section of the metal being forged at the bends therein, the section of the metal being taken along line 2--2 of FIG. 1, the view being on a larger scale than in FIG. 1;

FIG. 3 is a perspective view of a fragment of metal having two right angle bends and which was formed from a flat strip of sheet metal by cold working machinery;

FIG. 4 is a diagrammatic view of the forging elements and of a heating element used for preheating the metal prior to subjecting the same to the forging elements;

FIG. 5 is a perspective view of a fragment of a strip of metal which was preformed by cold working machinery from a flat strip of sheet metal and showing diagrammatically the grain structure and the fissures resulting from the bending of the metal during the cold working;

FIG. 6 is a perspective view of the sheet metal after the forging operation, again showing the grain structure as being in interlocked, forged state at the bends;

FIG. 7 is a perspective view of a fragment of a W-shaped strip of metal which was formed by cold working machinery from a strip of sheet metal;

FIG. 8 is a view similar to FIG. 2 but showing forging elements for forging the bends of the W-shaped sheet metal shown in FIG. 7;

FIG. 9 is a perspective view of a fragment of an L-shaped strip of metal which was formed by cold working machinery from a strip of sheet metal;

FIG. 10 is a view similar at FIG. 2, but showing forging elements for forging the bend of the L-shaped sheet metal shown in FIG. 9; and

FIG. 11 is a perspective view of a fragment of a bar of metal showing in dot and dash lines the metal which had to be removed by machinery to fonn the strip shown in full lines.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more in detail to the drawings, the machine 20 for carrying out the invention comprises two metal shaping elements 22 and 24.

The element 22 includes a groove formed by a base 26 which merges with cheeks 28 and 30 having confronting surfaces 32 and 34, respectively.

The element 24 includes a centrally disposed section 36 and integrally formed side sections, the left section being shown at 38 and the right section being shown at 40. As shown more clearly in FIG. 1, the lower end surfaces or portions 42 and 44, respectively, of section 38 and section 40 are spaced upwardly from the lower end surface 46 of the centrally disposed section 36.

The metal 45 to be shaped may be preformed as shown in FIG. 3 from a strip of sheet metal by cold working machinery. After being heated to a temperature at which the metal is in a forgeable state, it is fed into the element 22. After being so fed, it is subjected to pressure between elements 22 and 24. To accomplish this, element 24 is extended into the groove in element 22, and it spans the width of the groove. When so inserted, the lower surface or portion 46 of the section 36 is spaced from the top surface of the base 28 of element 22, and the sections 38 and 40 are spaced a greater distance from the top surface 26 of element 22. The outer side faces 48 and 50, respectively, of sections 38 and 40 of element 24 are juxtaposed the confronting surfaces 32 and 34, respectively, of the cheeks 28 and 30.

Referring now to FIG. 5, the strip of metal 45 is shown after it has been preformed by cold working machinery from an elongated strip of sheet metal. As an example, the strip is preformed into flanges 51 and 52 which are interconnected by the bent portions 53 with the base 54. The general longitudinally extending grain structure is shown by the double dot and dash lines 55. The cold bending operation often causes grain growth resulting in ruptures or fissures shown by lines 56. Obviously, the more acute bending causes greater grain growth and wider ruptures and fissures.

Such acute bending by cool working is shown in FIG. 3. The metal 45, after assuming the shape shown in FIG. 3 by cold working, is pressed downwardly into the groove in element 22 by the element 24. When under this pressure, the bottom portions 42 and 44 of sections 38 and 40 upon engaging the upper edge surfaces of the flanges SI and 52 of the metal 45, are forced against the surface 46 of element 22, and since the bend 54 of metal 45 is confined between the surface 26 and confronting surfaces 32 and 34 of the element 22, the heated metal will flow toward the bent ends 53, resulting in interlocking, forged grain structure as shown by the cross double dot and dash lines 57in FIG. 6.

By virtue of the present invention, the preforming of the sheet metal strip to its approximate ultimate shape is effected quickly and at a relatively low labor cost by standard cold working machinery. Thereafter, all ruptures or fissures created at the bends are eliminated by the aforedescribed method. The entire preshaped strip can be heated, or the area of the bends only can be heated to a temperature at which the metal is in a forgeable state. For example, sheet steel should be heated to between l,900 and 2000 Fahrenheit.

When relatively thick metal is to be shaped, I prefer to form the elements 22 and 24 as metal rollers as herein shown. These rollers are rotated by shafts 58 and 60, respectively. The roller 22 is provided with a circular groove concentric with the axis of shaft 58. The bottom of the groove forms the base 26 which merges with the confronting cheeks 28 and 30. The roller 24 extends into the groove in roller 22. It spans the groove and is provided with three circular sections 36, 38 and 40 which are concentric with the axis of shaft 60. The outer surfaces or portions 42 and 44, respectively, of sections 38 and 40 are spaced axially inwardly from the outer surface 46 of central section 36.

The heating element may be of any standard type such as a furnace or an induction heater or a series of induction heaters. Such heating element is shown diagrammatically in FIG. 4 at 64.

As aforementioned, heretofore when it was necessary to form a strip of metal having fissure-free comers, the entire strip was forged or the finished strip was machined from bar stock such as that shown in FIG. 11 at 70. If a finished strip was desirable having the shape like that shown in FIG. 3 or FIG. 5, and which in FIG. 11 is shown by the full perimeter and dotted lines, the material indicated by dot and dash lines 72 in FIG. 11 had to be removed from the bar stock by, for example milling machinery and the removed material was scrap metal.

The complete forging heretofore practice was a highly expensive operation, and the removal of material by milling was a slow and expensive process. Too, the removed material had only a scrap metal value.

It will be understood that strips of many different configurations can be formed by following the herein-defined process and by similar forging elements. One example is shown in FIGS. 7 and 8. In these FIGS., the elongated strip 74 is W- shaped having acute bends 76, 78 and 80. It is first preformed to the shape shown in FIG. 7 by standard cold working machinery such as a press brake and rollers. Thereafter, after being heated to a temperature at which it is in forgeable state, it is subjected to forging elements such as roller 82 having a circular groove 84, the peripheral surface of which complements the ultimate desired outer surfaces of the strip 74 and a roller 86 which spans the groove 84 and has a circular peripheral surface which complements the ultimate desired outer surface of the strip 74. These surfaces of the rollers 82 and 86 are concentric with the axes, respectively, of the shafts 88 and 90 for rotating the same. Upon completion of the roller operation, the bends 76, 78 and 80 will have been forged as previously explained, i.e., those bends will be forged like that shown at 57 in FIG. 6.

Referring now to FIG. 9, a sheet metal strip 92 has an ultimate L-shape and is provided with an elongated bead 94 at the junction of legs 96 and 98 of the strip. In this embodiment, the strip of sheet metal is preformed as shown in FIG. 10. After being heated to foregeable state, it is subjected to the forging rollers 100 and 102 which are rotated by shafts I04 and 106, respectively. The roller 100 includes two cheeks 108 and 110 having confronting surfaces 112 and 114, respectively. The connecting section 116 is provided with a circular groove 118 along the surface 112 of check 108. The groove forms a surface which confronts surface 112. Bead 94 is formed by extruding metal from the leg 96 into the groove 1 18.

The forging roller 102 is provided with two peripheral surfaces 120 and 122 which complement the ultimate desired inner surfaces of the strip 92.

After heating, as previously explained, the strip 92 is subjected to forging rollers and [02 whereby pressure is applied by eripheral surface to the inner side of le 98 and y perip era surface 122 to the upper edge of leg 6. The

metal will flow toward the bead 94 due to the pressure exerted by peripheral surface 122, and, since the right edge of leg 98 is confined by check 112 of the roller 100, the pressure exerted by peripheral surface 120 causes metal of leg 98 to flow to the left. Thus pressures on the upper edge of leg 96 and on the top or inner surface of leg 98 cause metal to flow toward bead 94 and simultaneously effect interlocking, forged grain structure throughout the length of bead 94.

Having described my invention, I claim:

1. The steps in the method of forging the bend in a metal having flanges, which steps consist in:

A. heating the metal at the bend to a temperature at which it is forgeable;

B. causing the heated metal to move through a grooved element;

C. causing the heated metal to flow toward the bend and preventing the flow of the metal away from the bend by applying pressure to the free edges of the metal while the metal is in the groove.

2. The steps in the method as defined in claim 1, characterized in that the grooved element is a roller.

3. The steps in the method as defined in claim 1, characterized in that the application of the said pressure is through a roller extending into the groove.

4. The steps in the method as defined in claim 1, characterized in that the grooved element is a roller and the application of the said pressure is through a roller extending into the groove.

5. The method of shaping sheet metal to an ultimate shape, the metal having flanges extending from a bend in the metal which method consists in:

A. preforming the sheet metal, by cold working, to the approximate ultimate shape desired;

B. thereafter heating the metal, at least at the bend thereof, to a temperature at which the metal is in a forgeable state;

C. causing the metal to move through a grooved element;

D. causing the heated metal to flow toward the bend and preventing the flow of the metal away from the bend by applying pressure to the free edges of the metal while the metal is in the groove.

6. The steps in the method as defined in claim 5, characterized in that the grooved element is a roller.

7. The steps in the method as defined in claim 5, characterized in that the application of the said pressure is through a roller extending into the groove.

8. The steps in the method as defined in claim 5, characterized in that the grooved element is a roller and the application of the said pressure is through a roller extending into the groove.

9. Mechanism for forging metal at the bends between flanges in sheet metal, comprising in combination:

A. means for heating the metal, at least at the bend, to a temperature at which the metal is in a forgeable state;

13. an element having a groove for receiving the heated metal;

C. means for causing the flow of said metal toward the bend therein and preventing the flow of the metal away from the bend, including a second element extending into the groove and engaging the free edge surface of one of the flanges for forcing the metal toward said bend and engaging the free edge surface of the other flange.

10. Mechanism as defined in claim 9, characterized in that the first mentioned element is a grooved roller.

11. Mechanism as defined in claim 9, characterized in that the second mentioned element is a roller.

12. Mechanism as defined in claim 9, characterized in that one of the cheeks of the grooved element prevents flow of the metal in a direction opposite the first mentioned flow. 

1. The steps in the method of forging the bend in a metal having flanges, which steps consist in: A. heating the metal at the bend to a temperature at which it is forgeable; B. causing the heated metal to move through a grooved element; C. causing the heated metal to flow toward the bend and preventing the flow of the metal away from the bend by applying pressure to the free edges of the metal while the metal is in the groove.
 2. The steps in the method as defined in claim 1, characterized in that the grooved element is a roller.
 3. The steps in the method as defined in claim 1, characterized in that the application of the said pressure is through a roller extending into the groove.
 4. The steps in the method as defined in claim 1, characterized in that the grooved element is a roller and the application of the said pressure is through a roller extending into the groove.
 5. The method of shaping sheet metal to an ultimate shape, the metal having flanges extending from a bend in the metal which method consists in: A. preforming the sheet metal, by cold working, to the approximate ultimate shape desired; B. thereafter heating the metal, at least at the bend thereof, to a temperature at which the metal is in a forgeable state; C. causing the metal to move through a grooved element; D. causing the heated metal to flow toward the bend and preventing the flow of the metal away from the bend by applying pressure to the free edges of the metal while the metal is in the groove.
 6. The steps in the method as defined in claim 5, characterized in that the grooved element is a roller.
 7. The steps in the method as defined in claim 5, characterized in that the application of the said pressure is through a roller extending into the groove.
 8. The steps in the method as defined in claim 5, characterized in that the grooved element is a roller and the application of the said pressure is through a roller extending into the groove.
 9. MechaNism for forging metal at the bends between flanges in sheet metal, comprising in combination: A. means for heating the metal, at least at the bend, to a temperature at which the metal is in a forgeable state; B. an element having a groove for receiving the heated metal; C. means for causing the flow of said metal toward the bend therein and preventing the flow of the metal away from the bend, including a second element extending into the groove and engaging the free edge surface of one of the flanges for forcing the metal toward said bend and engaging the free edge surface of the other flange.
 10. Mechanism as defined in claim 9, characterized in that the first mentioned element is a grooved roller.
 11. Mechanism as defined in claim 9, characterized in that the second mentioned element is a roller.
 12. Mechanism as defined in claim 9, characterized in that one of the cheeks of the grooved element prevents flow of the metal in a direction opposite the first mentioned flow. 